This move will likely save her multi-millions on her U.S. tax bill, tax lawyers told Reuters.

Interestingly, Rich's ex-husband, Marc Rich was pardoned by former President Bill Clinton on his last day in office in 2001; among the charges Marc Rich was indicted on was tax evasion before he fled the country in 1983.

A House of Representatives committee investigation looked into the pardon and concluded Denise Rich's contributions to Clinton's presidential campaign and his library influenced his decision to pardon Marc Rich.

The 68-year-old Denise Rich, who has Austrian citizenship through her late father, dumped her U.S. citizenship in November, according to her lawyer, Reuters reports.

Her maiden name, Denise Eisenberg, showed up on the same quarterly list in the Federal Register of Americans who have renounced their citizenship, the same list that featured Facebook co-founder Eduardo Saverin, who renounced his citizenship in anticipation of Facebook's initial offering in May.

Rich's lawyer told Reuters she made the move "so that she can be closer to her family and to Peter Cervinka, her long-time partner."

Cervinka is Austrian but lives in London. Reuters reports that as an Austrian citizen, Rich would be able to take advantage of Austrian tax laws, which gives large tax breaks to its citizens who live half the year out of the country.